>>What on earth comfort can you derive from this? Earlier glaciations took
place when the sttructure of continents was sifferent and the North
Atalantic thermohaile simply wasn't there; and this is the main stbilising
mechanism in the modern climate-system. <<
Mark,
I wasn't trying to draw comfort, but to show the actual state of
scientific knowledge by pointing out some of the contradictions and
limitations of the article by a scientist which you yourself posted to show
us how definitive the science has become. I sought to demonstrate by
examining it closely that the article quite clearly and openly speculated,
and all in one direction; it examined the evidence about past climate, etc.,
strictly from a "global warming" perspective. This is a perfectly legitimate
exercise, of course, in scientific discourse, but it does tend to confirm
that the science is very, very far from being definitive.
>>But we just do know, that
for instance the Arctic ice cover will disappear _in the next 2 decades_ and
that the North Atlantic thermohaline is already shutting doww. <<
Do we actually *know* these things? The article you posted which was a
review of the global warming literature did not, I don't think, contain
these predictions.
But are these two predictions actually even compatible with each other? If
you shut down one of the great conveyor belts of heat from the tropics to
much higher latitudes, wouldn't you instead get a significantly colder
climate? Isn't that precisely the mechanism being studied for "climate
flipping" and a new ice age?
>>Jose, temperatures have risen dramatically; spring comes early in London
now, and winter doesn't even exist. And the mnost recent models explain
well, fit the known record well, and are able to predict exactly what HAS
occurred from a starting point of 1750 (for example). You are clutching at
straws.<<
I was commenting upon the evidence as presented in the article you provided;
I have actually done no *independent* temperature studies of my own, but it
seemed to me not entirely without significance that the review of the
literature and current state of the science article you provided did not
make any claims that the empirical data support the global warming
hypotheses; on the contrary, it seeks to defend the hypotheses from the
impression that the data refutes it, explaining why the amount and nature of
the data we have might well be too limited for our purpose.
It's been my experience is these discussions in the past that people get the
*impression* such and such a study or finding is much more definitive than
it is, thanks to the utter incompetence and stupidity of the bourgeois
press. Today, thanks to the Internet, we often have access to the study
itself and even the underlying data, unfiltered by the extremely narrow
mental bandwidth of bourgeois newspaper hacks and the actors who play
reporters on the TV. Thus, for example, in the past couple of years there
have been various accounts in the bourgeois press mistakenly claiming the
satellite data now confirm global warming, which is a result of the
reporters simply not understanding the explanations from the scientists
involved about the limitations of the data set.
What that data set shows is that the most significant thing to note about
global warming is that, if it IS what is going on, it is occurring through
a mechanism we do not understand. The global warming hypothesis is based on
the greenhouse effect; more heat will be "trapped" in the lower atmosphere
by the increased concentration of CO2.
Yet the best data we have fails to reveal significant warming of the lower
atmosphere, *precisely* where the heat would need to be trapped to impact
the surface. But there isn't any need to take my word for it. The data is
at:
http://science.msfc.nasa.gov/newhome/essd/essd_strat_temp.htm
The accompanying commentary says:
"This chart shows the monthly temperature changes for the lower
troposphere - Earth's atmosphere from the surface to 8 km, or 5 miles up.
The temperature in this region is more strongly influenced by oceanic
activity, particularly the "El Niño" and "La Niña" phenomena, which
originate as changes in oceanic and atmospheric circulations in the tropical
Pacific Ocean. The overall trend in the lower tropospheric data is
approximately steady, at about +0.047oC per decade. Click on the charts to
get the numerical data.
"Surface thermometer measurements indicate that the temperature of the Earth
is warming, while the satellite data show no significant long-term trends.
These differences are the basis for discussions over the existence and
magnitude of any global warming the Earth may be experiencing as a result of
human activity. This page, updated monthly, will continue to provide the
latest temperature measurements of various layers of the Earth's atmosphere
from space."
I should note that over the years, the "trend" in this data set has been
both positive and negative. Right now it is slightly positive, due
especially to the prolonged "El Niño" of the late 90s. Before then it had
been just a touch negative. The current "La Niña," which is lasting longer
than predicted, and which is associated with lower atmospheric temperatures,
is pulling the average down as those temperatures get folded into the
calculations. Hence the statement that the data "show no significant
long-term trends."
The main NASA page on global climate change has this to say:
"Temperatures measured at the earth's surface have been increasing by about
0.1 oC per decade for twenty years. Computer models of global warming
suggest that the lower atmosphere should be warming up as well, but
temperature measurements from space show otherwise. There has been no
systematic warming in the troposphere for the past 19 years, and the
temperature of the stratosphere is actually decreasing. Does this mean that
global warming is a myth? Probably not. Instead, say researchers, it shows
that the temperature structure of the atmosphere is more complex than
previously thought."
The URL is:
http://www.climatenews.com/
I highly recommend it. Following the links from that page you can get more
up to speed on a different type of anthropogenic climate change, the urban
heat island effect. This is important because it has to do with your comment
that "Spring comes early in London now."
That is the kind of anecdotal statement one constantly hears in these
discussions in the bourgeois press. And it is true that many urban areas are
hotter than they were even a quarter of a century ago, but the evidence is
overwhelming that this is due to the urban heat island effect. Thus last
year we were being warned about malaria outbreaks and God knows what else on
the eastern seaboard of the U.S., which some witless reporters attributed to
GLOBAL climate change when everything points to LOCAL climate change being
the overriding factor.
The fact is that in terms of HUMAN habitat the creation of
asphalt-and-concrete jungles and their spread is the main thing that is
impacting temperatures in urban areas where many people live. So when you're
sweltering in mid-summer heat, don't look up and curse the CO2 in the
atmosphere, look down and around and curse all the asphalt and pavement that
surrounds you.
The science on this seems quite conclusive and even non-controversial, so,
of course, it gets zero play in the bourgeois press.
Then you quote this paragraph which was in my post:
> Those who challenge greenhouse warming predictions point to such
> patterns as
> indications that the model predictions are seriously in error.
> However, most
> climatologists point out that natural oscillations of a decadal-scale can
> modify a greenhouse warming signal during the present, relatively early
> stage of the perturbation. This is but one example where an historical
> perspective can give insight into what at first appears as a troubling
> discrepancy between models and observations.
To which you reply:
>>What are you reading? This sounds like the kinds of things Global Climate
Coalition types like Fred SDinger were able to get away with in 1995, but
not any more. You'll just oblige me to spend today and tomorrow bombing the
list with the by-now MOUNTAIN of evidence which exists and shows clear and
unchallangeable (except by lunatics) evidence of global warming which will
produce mean temperature of 2-8C this century.<<
Well, actually, I didn't write that objectionable paragraph, it is from the
article by the supporter of the global warming hypotheses which YOU posted
for MY edification. The further away you get from certain environmental
groups and the vulgar bourgeois press and the closer you get to what
scientists have actually been writing and saying over the years, the clearer
it becomes that a lot of the science is extremely *tentative* and
*unfinished.*
As for the Global Climate Coalition and Fred Singer, I don't think I've ever
read any of their material, and have no idea what they "got away with" five
years ago or today. The main thing I try to look at from time to time is the
data series put out by NASA, and the accompanying commentary, partly because
I had a chance to interview some of the researchers involved and they struck
me as very level-headed, objective, sober people, partly because it seems to
me that is the key data.
José
----- Original Message -----
From: "Mark Jones" <jones118 at lineone.net>
To: <marxism at lists.panix.com>
Sent: Thursday, June 08, 2000 4:55 AM
Subject: RE: Mark's environmental panic attack
Jose G. Perez wrote:
>
> Notice the construction of the argument. The evidence is temperatures
> were 1-2 degrees centigrade higher. There is less evidence to show this
> occurred simultaneously. But reading all the fine print which I don't
> reproduce here, there is also less evidence to show this DID NOT occur
> simultaneously. Assigning processes dates is just too dicey. So
> in terms of
> global temperature change the Eemian could well have been very much
> different from the present, or could well NOT have been much
> different from
> the present. We just don't know.
What on earth comfort can you derive from this? Earlier glaciations took
place when the sttructure of continents was sifferent and the North
Atalantic thermohaile simply wasn't there; and this is the main stbilising
mechanism in the modern climate-system. So there is no basis for comparison.
Whatever we do know is that the system seems to have a number of different
equilibrium states and thatb changes between them tend to be abrupt. The
last Ice Age ended suddenly but came back equally suiddenly for a while
after collapsing ice sheets over N America launched huge quantities of fresh
water into the Atlantic which temporarily reversed the Gulf Stream causing
renewed glaciation which however soon gave way and the modern climate was
established. These gigantic natural processes are obviously not consistent
with sustaining human civilisation. In a new Ice Age London will be under a
mile of ice. I won't be able to sit in the British Library discussing these
things with you any more. Your own plight won't be any better. Possibly
humans will survive but how, under what conditions is another matter. Your
position amounts to saying 'We just don't know'. But we just do know, that
for instance the Arctic ice cover will disappear _in the next 2 decades_ and
that the North Atlantic thermohaline is already shutting doww. Since there
seems to be no equivalent in the geological evidene to the massive and
sudden release of GHG caused by fossil burning, there are no anaologies
which we can learn from about the likely outcome of climate flipping in a
carbon-rich atmosphere; but do we really wanna make the experiment? I don't
think so.
>> Another example:
>> An application of our understanding of ten to 100 year variability may
> be
> found in the present debate over several features of the
> temperature history
> of the last 100 years, and the fact that surface temperature has not
> consistently risen during this time at the rate predicted by simple
> greenhouse warming. The period from the 1950s through the early 1970s
> exhibited a cooling trend; and while global temperatures have
> been high over
> the last fifteen years, they have also been relatively stable.
>
Jose, temperatures have risen dramatically; spring comes early in London
now, and winter doesn't even exist. And the mnost recent models explain
well, fit the known record well, and are able to predict exactly what HAS
occurred from a starting point of 1750 (for example). You are clutching at
straws.
> Those who challenge greenhouse warming predictions point to such
> patterns as
> indications that the model predictions are seriously in error.
> However, most
> climatologists point out that natural oscillations of a decadal-scale can
> modify a greenhouse warming signal during the present, relatively early
> stage of the perturbation. This is but one example where an historical
> perspective can give insight into what at first appears as a troubling
> discrepancy between models and observations.
What are you reading? This sounds like the kinds of things Global Climate
Coalition types like Fred SDinger were able to get away with in 1995, but
not any more. You'll just oblige me to spend today and tomorrow bombing the
list with the by-now MOUNTAIN of evidence which exists and shows clear and
unchallangeable (except by lunatics) evidence of global warming which will
produce mean temperature of 2-8C this century. Nothing like this has
happened before in the history of the planet! BTW the Reflections piece is
also old and I should have posted updated evidence. But the main line of
argument stands. Check out the OAAA or other websites.
>> Were "natural" climatic variations of the sort that have characterized
> One very significant
> problem is that
> there is as yet no clear understanding of the
> evaporation-cloud-precipitation cycle and whether it is a net
> plus or minus
> on global warming.
No, there's a mass of new stuff out there. I'll have to dig it out, I guess.
>> I suspect at some point it has to become a negative feedback element,
> for, clearly, something prevented a runaway "venus" effect when CO2 levels
> were several percent in the atmosphere. Evaporation cools the surface and
> takes the heat up where it can be more easily dissipated. Clouds reflect
> sunlight but at the same time trap heat. How it all shakes out at the end,
> that's the $64,000 question on global warming.
Unfortunately runaway warming *is* a possibility, if for example the
astonishing increases in methane emissions do not abate, and if (worst case
scenario) methane hydrates are released from the Arctic seabed by warming.
>> I continue to insist that the evidence suggests that there is a strong
> and as yet not understood mechanism or series of mechanisms that keeps the
> earth within a *relatively* narrow range of temperatures. You argue that
> instead there are "frightening" lurches back and forth. Yes,
> there are, but
> the point is these never go into full, runaway mode.
Look, it's no comfort to suppose that all we'll get is your typical Ice Age.
Imagine we already had world socialism. Science and technology would serve
different fucntions and would be less imbricated into everyday life. If
global warming was seen to be the problem is it, we would not experiment on
the planet on the present trial and error method, ie, we've kicked it a few
times and it ain't dead yet, so let's kick it some more and see what
happens. A socialist world would not be driven by the same urgent drives and
crises; it might be possible to sopend a century or more using science to
learn about how biospheric and biogeochemical processes actually work;
humankind might really become the guardians and guarantors of life on earth.
What is actually happen is something truly horrible and it is going to wreck
the natrual world even while industrial capitalism collapses, which it is
going to do in the next few decades.
You insist that the
> reflection of sunlight from the surface by ice isn't enough to
> cause runaway
> glaciation. But, clearly, something HAS been causing ice ages. So far the
> explanations for both the ice ages and their ending are speculative,
> nothing is known for sure. The main argument for their being linked to
> changes in the earth's orbit and axis of rotation in relation to
> the sun is
> their recurrent, periodical nature.
>
What does it mean, speculative? Do you simply reject all modelling out of
hand?
Check out the Jonathan Adams webpages I posted the other day on the
CrashList, in particular this:
THE CARBON CYCLE AND THE NUMERIC MODELLING CULTURE.
http://chomsky.arts.adelaide.edu.au/Geogenvst/adams/ccmodel.htm
In it Adams critiques 'the modelling culture' using the kinds of arguments
you do. But he does not argue it's a waste of time, for all that.
[1] THE ROLE OF TERRESTRIAL ECOSYSTEMS IN GLACIAL-TO-INTERGLACIAL CHANGES IN
THE GLOBAL CARBON CYCLE: AN APPROACH BASED ON RECONSTRUCTION OF
PALAEOVEGETATION.
L'INFLUENCE DES ECOSYSTEMES TERRESTRES SUR LES CHANGEMENTS DU CYCLE GLOBAL
DU CARBONE, ENTRE LES ERES GLACIAIRES ET INTERGLACIAIRES: UNE APPROCHE PAR
LA RECONSTRUCTION DE LA PALEOVEGETATION.
Par: Jonathan M. Adams.
Laboratoire de Géologie du Quaternaire, Université de la Méditerranée de
Aix-Marseille II, Faculté des Sciences, CNRS Luminy, France.
THE ROLE OF TERRESTRIAL ECOSYSTEMS IN GLACIAL-TO-INTERGLACIAL CHANGES IN THE
GLOBAL CARBON CYCLE: AN APPROACH BASED ON RECONSTRUCTION OF
PALAEOVEGETATION.
L'INFLUENCE DES ECOSYSTEMES TERRESTRES SUR LES CHANGEMENTS DU CYCLE GLOBAL
DU CARBONE, ENTRE LES ERES GLACIAIRES ET INTERGLACIAIRES: UNE APPROCHE PAR
LA RECONSTRUCTION DE LA PALEOVEGETATION.
Par: Jonathan M. Adams.
Laboratoire de Géologie du Quaternaire, Université de la Méditerranée de
Aix-Marseille II, Faculté des Sciences, CNRS Luminy, France.
EXTENDED ABSTRACT IN ENGLISH
Explaining the CO2, methane and climate changes recorded in ice cores is a
matter of key interest if one is to understand the workings of the Earth's
climate system. From a review of the distribution of vegetation at various
intervals over the last 20,000 years, it has been possible here to make some
deductions about the role of the land system as a modifier of atmospheric
composition and climate on the glacial-interglacial timescale.
>From the mapping results presented in this thesis, it appears that during
the extremes of glacial phases, such as the Last Glacial Maximum (LGM,
approximately 20,000 calendar years ago or 18,000 radiocarbon years ago),
the world's land surface would have been much colder and drier than at
present. Deserts were much more widespread, and forests were very restricted
in distribution. Peatlands seem barely to have existed at all. Comparing
this peak glacial state with the peak interglacial state of 8,000 - 5,000
years ago, it seems that total land organic carbon storage in vegetation,
soils and peatlands more than doubled between glacial and interglacial
conditions. This would have involved an increase of around 1700 GtC (the
extreme outer limits on this figure are suggested as being 1000-2300 Gt),
considerably larger than other estimates have suggested.
Other sinks of carbon on land were also stronger during interglacial
conditions. The rate of carbon dioxide uptake by biologically-catalysed rock
weathering seems likely to have doubled or tripled between full glacial and
interglacial conditions. The dissolved carbon reservoir in groundwater and
the sediment carbon in lake beds was also probably significantly larger
under moist Holocene conditions than during the dry LGM.
The combined picture obtained from all these terrestrial sinks is that a
great deal of carbon (at least 1000 Gt, and possibly more than 1700 Gt) was
in effect 'missing' from the land-atmosphere system at the LGM compared to
the Holocene, in addition to the 'missing' 160 Gt of carbon in the form of
lower glacial CO2 levels. The only plausible explanation is that all or most
of this carbon was being held within the oceans, to be released as the
interglacial began.
[cont at: http://www.esd.ornl.gov/~vxk/thesis.html]
[2] Three papers on carbon sequestration:
AN ESTIMATE OF VOLATILE ORGANIC COMPOUND EMISSIONS FROM NATURAL VEGETATION
SINCE THE LAST GLACIAL MAXIMUM.
http://chomsky.arts.adelaide.edu.au/Geogenvst/adams/pvoc3-99.htm
THE CARBON CYCLE AND THE NUMERIC MODELLING CULTURE.
http://chomsky.arts.adelaide.edu.au/Geogenvst/adams/ccmodel.htm
A PRELIMINARY ESTIMATE OF CHANGING CALCRETE CARBON STORAGE ON LAND SINCE THE
LAST GLACIAL MAXIMUM
http://chomsky.arts.adelaide.edu.au/Geogenvst/adams/ccarbon.htm
[3]
Did Indo-European Languages spread before farming?
Jonathan Adams, MS 6335, Environmental Sciences Division, Oak Ridge National
Laboratory, Oak Ridge, TN 37831, USA (e-mail; Jonathan at elvis.esd.ornl.gov)
and
Marcel Otte, Université de Liège, Service de Préhistoire, place du XX Août
7, Bâtiment A1, 4000 Liège, Belgium. (e-mail; prehist at ulg.ac.be)
Abstract: The late Glacial record of vegetation and climate suggests that
major changes in hunter-gatherer population density might have occurred
across Europe and Asia as a result of extreme climate fluctuations. We
hypothesise that a reduction in population density across most of the region
during the coldest part of the Younger Dryas (around 12,800-11,400 cal.
y.a.) may have been followed by a sudden rebound phase, when climate
switched back to warm, moist Holocene conditions over only a few decades. A
'sparse wave' of hunter-gatherers migrating rapidly out of a refugial area
(possibly located in southern Europe and/or the Near East) would have made a
disproportionate contribution to the genetic and linguistic legacy of the
region. This may explain part of the initial prehistoric dispersal pattern
of the Indo-European languages. Other smaller and somewhat later climate
changes, such as the cold event at 8,200 cal. y.a., are also candidates for
this process of regional depopulation followed by repopulation from a
restricted source region. The possibility should be considered in addition
to hypotheses invoking spread of these languages by early farmers or warlike
cultures. [cont at: http://www.esd.ornl.gov/projects/qen/Indo2.html]
Mark Jones
http://www.egroups.com/group/CrashList
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